Photographic enlarging apparatus



1922 2 smid-sneu 1 Swanton WIW@ dike June 17 1924.

w. T. MOHLER PHOTOGRAPHIG ENLARGING VAPPARATUS Filed Jan. 1'7,

w. T. Mop-:LER

PHOTOGRAPHIC ENLARGING APFARATUS .Filed Jan. 17, 192'2 a shuts-shew@ Ill 3 WMM.

Patented June' 17, 1.924.

UNI-'ran STATES A, 1,498,472 Param'- orales.

wILLmJr rr. nonnen., or rnmrom, manana.

rnoroeaarmc ENLABGINQ Arnhems.

Application Bled January 17, 1922. `keria] No.4 529,881.

-is a specification, reference being had,- therein tothe accompanyingdrawings.

The invention relates to photogra hic enlargin machines, and has for itso ject to provi e a device of this character wherein the focusing of themachine is automatically accomplished through'the movement of the`cam-during the vertical adjustment or positioning of the enlargingcamera.

A further object is to provide a -photographic enlarging apparatuscomprising a vertically disposed standard, a vertically movable carriagecarried-thereby and moved upwardly or downwardly by an endless chainpassing overs' rockets, one of'which sprockets is provide with a crank.Also to rovide the vertically disposed standard wit a rack, which rackmeshes with a gear of a gear train carried by the carriage, said geartrain actuating a cam cooperating with vertically movable means wherebythe oous pa r 4.

' gne bellows 8 of the enlarging camera 6 85 .is provided with ahorizont-ally disposed of the camera is varied accordin to the posiltionof the carriagemon the stan ard.

A further objectis to provide the chains with adjustable counterweightsfor counterweightin -the carriage.

With t e above and other ob'ects in view the inventionresides in the comination and arrangement of parts as hereinafter set forth shown in thedrawin s, described and claimed, llt-bein underst o the preciseembodiment of the invention' that changes in may be made within thescope of what is claimed without departing from the .spirit lof theinvention.

In the drawings Figure 1 is a side elevation of themadesignates the baseof the machine, and 2v the vertically disposed standard T-shaped inhorizontal cross section. The base -1 is rovided with a .platform 3 onwhich a sheet of photographic paper 4 isI at ormA and on which sheet anenlarged vision from the plate 5 is projected from the enlarging camera6 through the lens 7. During an enlargmg operation it is necessary toproperly 00 focus the lens 7 by a movement of the bellows 8, accordintothe size of the enlargement and accor ing to the distance Vof theplate 5 from the sensitized papers 4. To accomplish the above resultssimultaneousl ,the camera 6 is mounted o n a horizontal y disposed arm 9of a carriage 10, which carriage is vertically movable on the flanges11y of the T-shaped standard 2, and is guided thereon by anti-frictionalbearings 12. rIfhe carriage 10 has connected thereto lat 13, the ends 14of sprocket chains 15. The sprocket chains 15 extend upwardly and oversprock- .ets 16 carried by the rearlwardly extending flange 17 of thestandard 2, and thence 75 downwardly over s rockets 18, and upwardly andhave thelr ends connected at 19 to the lower end of the carriage 10. Itwill be seen that when the crank handle 20 is rotated bythe operator,that the carriage 10 8o will be moved upwardly or downwardly, therebypositioning the enlarging camera 6 at various elevations above thephotographic member 21, which is slidably mounted on vertically disposedguide rods 22` 'which rods arel braced at their lower ends by passingthrough spaced' parallel arms 23 eX- 90 tending outwardly from acarriage 10.

When the enlarging camera 6 is moved u wardly, it is necessary for thebellows to collapsed for properly focusing the lens 7, and to accomplishthis result simultaneously and automatically with the upward movement ofthe carriage 10 in the direction of the arrow c, and to also provide ane focusing, a rack` 24 is provided en the inner face of the standard 2,which rack has-meshing therewith a gear 25, which rotates inthedirection of the arrow b. The gear 25 is carried by the carriage 10 andis rotatedin the direction of the arrow b von ,an upward movement of thecarriage 16. Rotatably namurteclA between `the arms 93 iS Marge geel' 26which is rotated in the direction of the arrow c when the gear 25rotates in the di` rection of the arrow b and rotates a gear 27 in thedirection of the arrow ev through the 110' medium of the small gear 28..Byv ,formin the gear train as above described from sms.

and large gears, it will be seen that the rotation ofthe gear 27 will bereduced in speed, thereby allowing a tine focus, as the focusingvariesin range in relation to the height of the carriage 10. To impartthe movement of the gear 27 tothe vertically movable member 21, the gear27 is provided with a cam 28a, which isengaged by a roller 29 carried bythe member 21. The cam moves upwardly/ in the direction of the arrow`f`in the operation above described and consequently causes the bellows 8to be collapsed for a long focus, the distance varying according to theelevation of the carriagey 10, and consequently the size of the enlargedobject is varied. Upon a downward movement of the carriage 10, the aboveoperation is reversed and the cam.28a moves downwardly in a directionVreversed to the arrow f, thereby shortening the focus by extending thebellows 8 downwardly.

- The chains 15 may be provided withv lcounterweights 30 whichcounterweight the i carriage 10 and allow the same to be held in raised-positions. However if so desired a cooperating ratchet 31 and dog 32may be provided on the sprocket 18 and flange 17, respectively of thestandard 2.

From the above it will be seen that a photographic enlarging machine isprovided, wherein upon a` raising of the enlarging camera, the focusing'of the camera will simultaneously and automatically take place, therebyallowin the operator to devote his attention entire to placing thesensitized paper and raising the camera to the proper elevation whichwill automaticallyfproperly focus the camera..

The invention having been set lforth what said ase, a carriageIvertically movable on the standard, means for movin lvertically, acamera carried y the carriage,-

a bellows carried by the'camera, a member carried by thelower end of thebellows, a

, lens carried by the lower end of the bellows,

said member carried by the lower end of the bellows. being verticallyguidable, a rack carried by the standard, a gear train in connectionwith said rack and means actuatedcomprising a base, a standard carriedby said carriage by the gear train whereby upon a movement of thecarriage the member carried by the bellows will be automatically movedand the lensv focused.

2. The combination with a photographic enlarging machine comprising avertically disposed standard, a carriage vertically movable on thestandard, means for moving` said carriage on the standard, an enlargincamera carried the carrlag'e and provide b with a bellows having a lensat its lower" end, a gear train carried by the carriage, said gear trainbeing connected to a rack carried by the standard, a cam `movable byVically ocusingthe lens upon a movement of the carriage, sai/dmeans-compr1s1ng a gear with which the cam train cooperating with a rackcarried by the standard, and a cam actuated by the gear trainand'cooperating with the bellows.

ln testimony whereof l hereunto atlix my signature.

WILLIAM T. MOHLER.'

